Apparatus for making a resin composite panel

ABSTRACT

The invention relates to a method of fabricating a fiberglass-resin impregnated composite article which has a non porous surface formed by melting and curing a suitable polymeric film thereon. The process further involves coating an adhesive layer having a release sheet thereon over the non-porous melted polymer surface for bonding onto a substrate, and the invention further relates to the particular formed article and a process of forming an air-conditioning frame.

This is a division, of application Ser. No. 267,281, filed Nov. 4, 1988,now U.S. Pat. No. 4,877,476.

FIELD OF THE INVENTION

The invention relates to a method of making a resin fiberglass compositewhich is particularly useful as a panel in construction applicationssuch as in an air-conditioning frame, a process of making the composite,and the fabricated composite article.

BACKGROUND OF THE INVENTION

A variety of building materials which utilize fiberglass resincomposites have been made for a multitude of construction purposes.Additionally, the use of polymeric materials as layers in constructionmaterials, panels, and the like is also well known. The resultantarticles exhibit a wide variety of different properties depending uponthe particular characteristics of the fiberglass fiber, resin utilized,and polymeric material incorporated therein.

Such articles are particularly useful in articles such asair-conditioning structures where the thermal and moisture resistantcharacteristics of resin-fiberglass composites are particularlyessential. Such composites are excellent insulators, as well as beingstrong, lightweight materials and therefore their use has attracted agreat deal of attention in the art. However, these composites arehampered by several problems, such as being non-porous so that liquidgradually permeates within and damages the article. Additionally,bonding such composite articles into structures in an efficient andeffective manner has also been a problem, since such materials requiresuitable adhesives to be coated thereon and must be protected from theenvironment until they are placed in a position of intended use.

Accordingly, there is a need to develop a panel useful in articles suchas an air-conditioning frame and the like for purposes relating toenhanced thermal and moisture treatment characteristics and also inother related construction environments. There is also a need to developan accompanying method of making such panels so a suitable fiberglasspanel can be constructed from fiberglass materials and resins, be madesufficiently non-porous on at least one outer surface and have aneffective adhesive bonded to an outer surface for utilization at thedesired time.

SUMMARY OF THE INVENTION

The invention comprises, in a first aspect, a method of making an airconditioning frame having an insulating article bonded thereon, which isparticularly adaptable for utilization in the construction of airconditioners, e.g., as a bulk head insulator for a conditioning frameand, in a broader embodiment, is also useful in a variety of otherarticles. This involves the steps of coating a resin-impregnated,partially cured (B-stage cured) fiberglass batt formed, e.g., into aplanar batt, on a first surface with a layer of compatible resin havinga sufficiently high viscosity so that during later processing andmolding the resin will not seep entirely through the composite. The battis preferably made from flame attenuated fiberglass of specificdimensions and it is preferred to use phenolic type resin binders. Thecoated resin on the surface must be compatible with the resin-fiberglasscomposite. Next, a thin, non-woven polymeric sheet is applied onto thecured resin layer, on top of the uncured resin, and the resultantarticle is then molded under elevated temperatures and pressures for asuitable time to cure the article and also so that the polymeric sheetmelts and forms a mechanical bond with the fibers at the surface of theresin fiberglass article, i.e., forms a non-porous zone at the surface.The resultant article is then removed from the mold and later a suitableadhesive, e.g., preferably a high solids content water based adhesive,is coated over the surface having the melted polymeric layer thereon.Preferably this layer is then coated with a release sheet such as a polycoated kraft paper sheet and the resultant article is then preferablydried to remove any moisture present therein.

In a second aspect the invention comprises a method of making a resinimpregnated fiberglass product having an outer surface which issubstantially non-porous, in which essentially the same procedure as setforth above is followed. It is preferred that the resin-fiberglass battis formed by impregnating flame attenuated glass fibers having suitableranges of length and diameter and then blending the fibers with asuitable binder resin, followed by forming and compressing the resultingmixture into a partially cured, i.e., B-stage cured resin impregnatedfiberglass batt. The process is conducted as before, although theresultant article is not utilized as an air conditioning panel.

In yet another aspect, the invention comprises a molded resin-fiberglassarticle having at least a first surface which is substantiallynon-porous and over which an adhesive layer for adherence to a desiredsubstrate is coated. The article comprises a base layer of a compressedresin-impregnated fiberglass batt having a thin zone adjacent thesurface in which the melted polymer has penetrated the surface fibers ofthe fiberglass batt to form a mechanical bond, with a suitable adhesivelayer for attachment to a substrate coated over this non-porous surfaceof the fiber glass batt. Preferably, a release sheet is positioned overthe adhesive.

BRIEF DESCRIPTION OF DRAWINGS

The best mode contemplated in carrying out this invention is illustratedand better understood by reference to the following detailed descriptionwhen considered together with the accompanying drawings, in which:

FIG. 1 is an exploded view of a structural sandwich for making thecomposite laminated article according to the invention.

FIG. 2 discloses a block diagram outline of a preferred process formaking the composite articles of the invention.

FIG. 3 discloses the resultant laminated structure of the article ofFIG. 1 after being fabricated by the process set forth in FIG. 2 of theinvention.

FIG. 4 discloses the laminated structure of FIG. 3 bonded to the insideof an air conditioning frame.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings, FIG. 1 discloses the particular layerswhich are formed according to the process of FIG. 2 to produce thearticle set forth in FIG. 3.

The structural sandwich 10 comprises a resin-impregnated fiberglass batt12 as a base layer which is formed and partially cured, i.e., cured tothe B-stage at either the immediate locale or at a different site. It isparticularly preferred to use a flame attenuated glass fiber attainablefrom Manville, Inc. under the trade name "Microlite uncured" or,alternatively, "Rotary uncured" which has a fiber length ranging from3/4 to about 2 inches, preferably 1 to 13/4 inch, and a fiber diameterranging from about 7.0 to 13 microns, preferably about 3.8 to 5.1microns, although for other applications a variety of different glassfibers may be used. The fiberglass batt is formed in conventionalfashion, with the fibers being placed in a mold and sprayed in the bedwith a suitable resin binder, preferably a phenolic resin, i.e., aphenol-phenolic, or phenol-formaldehyde resin such as the acidcatalyzed, water soluble phenolic formaldehyde resin sold by GeorgiaPacific, or the like. Preferably, the resulting fiberglass batts shouldcomprise about 13 to 20 wt % resin, most preferably 16 to 18 wt %, withthe remainder being glass fibers. The resulting composite can have adensity ranging from about 2 to 18 lbs./ft³, most preferably from about4 to 6 lbs./ft³. After mixing, the resulting article is processed into abatt as set forth in block 30 of FIG. 2, i.e., the batt is compressedand partially cured (B-staged cured) so that the resulting article hasthe desired width and thickness.

The second stage of the process, as indicated in block 32, involvescoating the layer 12 on a first, preferably planar surface by knowntechniques with an uncured resin layer 14, which is a resin compatiblewith the binder resin of the fiberglass-resin article 12. Mostpreferably, the resin layer 14 is the same resin as that used in thefiber resin layer 12, i.e., preferably a phenol-phenolic resin, althoughin the broadest embodiment any suitable binder resin which is compatiblewith the resin forming the fiberglass article layer 12 can be utilizedas layer 14. It is essential that the resin have a high enough viscosityso that upon application it will not permeate through the entire widthof the fiberglass resin layer 12 before molding and final cure. Layer 12can have a variety of thicknesses, but it is typically preferred to havethe thickness range from about 1/32 to 1 inch in dimension. It is alsopreferred that the coated resin layer 14 seep into the fiberglass layer12 to a depth of about 1/16 to 1/32 of an inch and in this immediatearea the resin content ranges, preferably, from about 22 to 24 wt % ofthe fiberglass resin composite.

Next, the process involves step 34 of coating the resultant article witha skin coat 16, which is a porous polymeric sheet of preferablynon-woven character. This sheet is preferably chosen from polymericfilms such as polyesters, polyamides such as nylons, acrylics, andmixtures of the above. The skin coat or polymeric sheet should beapplied in amounts ranging from about 0.5 to 10 ounces per square yard,most preferably about 0.5 to 4.5 ounces per square yard. It is anessential element of the process that sheet 16 must melt and flow intothe interstices of the surface fiberglass and bond thereto, so as toform a thin surface coating which is partially water impermeable, butwill allow water to evaporate through the coating. It is most preferredto use polyesters and nylons such as sold under the trade names of"Remey" by Dupont, "812 PES" by Fiber Dynamics, Inc. or "Lutrador 7230,7240 and 7250" sold by Lutravil as the skin coat 16.

The resultant article, comprising layers 12, 14 and 16, is next moldedto a desired thickness and shape, preferably about 1/8 to 1 inch totalthickness, at elevated temperatures and pressures. Preferably,temperatures ranging from about 350° to 550° F. can be utilized. Mostpreferably it is preferred to operate at temperatures of 375° to 475° F.at pressure ranges in the mold between 20 to 4000 psi to produce themolded, cured article. Typically this involves molding times rangingfrom about 1 to 5 minutes, preferably about 2 to 31/2 minutes. Duringmolding as mentioned above, the polymeric skin coat 16 melts and forms amechanical bond with the fibers at the immediate surface of fiber resinarticle 12, and also the resin in both fiberglass batt 12 and layer 14are completely cured during forming the laminated article in step 36.

Upon completion of molding step 36, the cured article is removed fromthe mold and after cooling, coated with a bonding adhesive in step 38,preferably with a release sheet 20 lightly adhered over the adhesivelayer 18. Adhesive layer 18 is preferably any of a variety of suitablehigh solids content water based adhesives which can securely adhere tothe molded fiberglass article and bond it onto a desired substrate forsecure, long-term use. It is preferred to use a water-base adhesivehaving a solids content of at least 30 wt % and preferably 48 to 65 wt%. Most preferably, it is preferred to utilize a water-based adhesivesold under the trade name "FW-627" which is commercially available fromFranklin International, Columbus, Ohio. The composition of FW-627 is asfollows:

    ______________________________________                                                        % BY WEIGHT                                                   ______________________________________                                        VM & P Napththa    2-3%                                                       Toluene            2-3%                                                       Antioxidant       0.1-0.5%                                                    C9 Hydrocarbon Resin                                                                            5-10%                                                       C5/C9 Hydrocarbon Resin                                                                         5-10%                                                       Zinc Rosinate      2-5%                                                       Cellulosic Thickener                                                                            0.5-1.5%                                                    Aliphatic Oil     5-15%                                                       Amorphous Silica  10-15%                                                      Defoamer          0.1-0.5%                                                    Ammonium Hydroxide                                                                              0.05-0.15%                                                  Water             40-50%                                                      Styrene-Butadiene Latex                                                                         5-15%                                                       ______________________________________                                         Weight per gallon = 8.8 pounds                                                Percent NonVolatiles = 45.5%                                             

Adhesive layer 18 can be coated onto the molded article by any of avariety of methods known to the art such as roller, knife, or spraybonding. Additionally, it is preferred to protect the adhesive layer byutilization of a suitable poly coated kraft sheet 20 such as that soldby Ludlow, Inc. of Ware, Mass., which is a 60 to 90 lb weight, polycoated kraft paper which is substantially moisture impermeable and iseasily removed from the resultant article 10 at the desired time of use.

Upon completion of bonding it is preferred to dry in step 40 the formedarticle 50 until all of the moisture dissipates out of the porous sideof the article, i.e., the side not bonded by the adhesive layer 18 andrelease sheet 20. However, the formed article 10 is capable of moderatevapor permeation through the untreated side 22 of the fiberglass layer12. It is preferred to utilize infra red heaters for about 2 to 5minutes at a temperature of about 350° to 400° F. Upon completion of thedrying step 40 the article is then cut to desired blocks and shapes andcan be utilized in a variety of construction-type applicationspreferably being bonded to a substrate which performs a significanttemperature dividing function such as that found in an air conditioningpanel.

FIG. 3 discloses the formed article 50, which first includes layer 52that is formed of fiberglass and cured in a resin matrix according tothe precise specifications set forth earlier. The upper section of layer52 is a thin, bonded zone 54 in which the non-woven polymer sheet 16 hasbeen melted and the resin binder layer 14 cured so as to form a thin,planar zone which is non-porous and contains the melted polymericcomponent mechanically bonded to the fibers in this resin concentratedarea. On top of layer 54 a thin adhesive layer 56 is bonded to themolded article and release sheet 58 is bonded to layer 56.

FIG. 4 discloses one preferred use of the formed article in whicharticle 50 has had its release sheet 58 removed so that the now surfaceadhesive layer 56 can be bonded to a desired substrate, such as, e.g.,the inside of an air-conditioning panel 60.

It is additionally to be appreciated that although the invention hasbeen described in terms of making a single unit, these blocks can belaminated to each other in varying lamination arrangements, as would beclear to one skilled in the art. Additionally, although it is preferredto produce a substantially rectangular array of planar blocks, it is tobe understood that a multiplicity of surface arrangements can be soutilized if desired. Additionally, it should also be appreciated thatsuch a panel can be utilized for a multitude of different applicationsbesides the ones indicated above and a variety of different fiberglassmaterials, binder resins, polymeric skin coats, adhesive laminatinglayers and release sheets can be so utilized in the invention. Also, inlike fashion the resultant process of fabrication can be modified in amanner apparent to one skilled in the art.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

I claim:
 1. A molded resin-fiberglass article having at least onesurface which is substantially non-porous, comprising,a base layer of aresin impregnated fiberglass batt, said batt including an upper surface,a lower surface and side surfaces, a zone adjacent the upper surface ofthe batt having a melted polymer incorporated therein and bonded to thefibers of the fiberglass batt to form a non-porous upper surface; anadhesive layer bonded to both the non-porous surface and to one of (1) arelease sheet and (2) a substrate.
 2. An article in accordance withclaim 1 wherein a non-porous release sheet is adhered to the adhesivelayer.
 3. An article in accordance with claim 1 wherein the adhesivelayer is bonded to a substrate, the substrate being the inside of an airconditioning frame.